1. Field of the Invention
The present invention relates to a dust seal of a suspension for use in a vehicle, that is, a shock absorber, and more particularly, to a dust seal structure for a shock absorber, which prevents dusts from being introduced between a piston rod and a cap member (base cap) attached over a base shell forming the outer appearance of the shock absorber.
2. Description of the Related Art
A conventional vehicle uses various kinds of suspensions for improving operational performance or a ride comfort. In particular, a suspension combined with a spring, that is, a shock absorber, is used between a vehicle wheel and a vehicle body in order to absorb a vibration or impact force.
In general, a shock absorber includes a cylinder filled with a working fluid, a piston installed at an end of a rod and reciprocating within the cylinder, and a valve installed in the piston.
In such a conventional shock absorber, as shown in FIG. 1, a rod guide 5 guiding a straight line movement of a piston rod 3, and an oil seal 7 sealing a working fluid filled within a cylinder are installed over a base shell 1 forming the outer appearance of the cylinder.
In addition, a cap member (base cap) 10 including a plurality of dust discharge openings 11 is covered over the base shell 1 in order to protect the rod guide 5 and the oil seal 7.
In the conventional shock absorber, however, dusts introduced between the cap member 10 and the piston rod 3 are not smoothly discharged. Therefore, dusts are accumulated on the oil seal 7, causing oil leakage. This oil leakage degrades the performance and durability of the cylinder.